Studies on Nanostructure Aluminium Thin Film Coatings Deposited using DC magnetron Sputtering Process

Synthesis of Al Thin Films with High Optical Transmittance by DC Magnetron Sputtering Process Parameter Optimization

“…Therefore, this experimental study as well as previous magnetron sputtering observations suggests using sputtering current instead of sputtering voltage as the basic deposition parameter for DC magnetron-based thin film deposition. C. Optimal and Surface Properties Aluminum (Al) thin film is widely used as back contacts, good light reflectors, and interconnectors in flexible device fabrication technology, so the overall transmittance of used Al films would significantly affect the device performance, especially in the case of solar cell applications [7], [10], [11], [13], [22]. As a result, the effects of deposition powers (80, 100, 120, and 140 W) at a constant working gas pressure (5 mTorr) on Al film's overall transmittance were analyzed with a UV-vis-NIR spectrometer shown in Fig.…”

“…The average optical transmittance in the visible wavelength region 400 ∼ 800 nm of deposited Al films at 80 W and 100 W deposition power is around 96% and 88%, respectively. However, the average transmittance in the wavelength region 400 ∼ 800 nm decreases from 96% to 73% with the increase of deposition power from 80 W to 140 W, which might be due to the increase in Al film thickness, crystal growth, sputtering rate, and grain size [3], [7], [9], [11]- [13], [18], [20], [22], [23]. The higher deposition power usually increases the adatom mobility, sputtering yield, and defects in crystal growth according to magnetron sputtering theory and experimental observations, which contribute to reducing the optical transmittance.…”

“…Due to the numerous applications of Al films in microelectronic devices such as back contacts, reflectors, interconnectors, and so on, the sheet resistance is a very important parameter of Al films to maximize device performance [7], [10], [11], [23]. To understand the sputtering power effects on sheet resistance (Ω/□) in parallel with film thickness, a four-point probe-based Al films' sheet resistance measurement was conducted shown in Fig.…”

“…To date flexible device fabrication technology in microelectronics, optoelectronic, and thin film solar cells-based devices has attracted huge attention for its lightweight, easy to fold, and lower fabrication cost [1]- [13]. Aluminum (Al) thin film is widely used in flexible device fabrication technology due to its superior electrical, optical, and thermal properties as ohmic contacts, Schottky contacts, gate electrodes, back contacts, interconnects, and good light reflectors [5], [7], [10], [11], [13]. Al thin films can be deposited on glass and polymer substrates to facilitate the fabrication of optical and microelectronic devices using DC (direct current)/RF (radio frequency) magnetron sputtering, thermal evaporation, and electron beam evaporation (e-beam) techniques [3], [4], [9], [14]- [17].…”

“…Therefore, it is very important to understand the influence of Al thin film deposition process parameters (sputtering power, sputtering pressure, deposition rate, and thin film thickness) on its micro-structural characteristics to enhance the functionality of Al thin films in different devices fabrication. A few researchers have conducted studies for Al thin film deposition on glass and polymer substrates using ebeam or thermal evaporation techniques and few researchers have reported Al thin film deposition process parameters on glass substrates using DC magnetron sputtering [5], [7], [10], [13]. However, the reported results to fully understand the DC magnetron-based Al thin film deposition process parameters are still in the infancy phase.…”